Ingesting live stream for Wowza HLS streaming

Hello,

Can anyone recommend a good system for ingesting multiple live analog and digital sources for delivery via wowza media servers? Something that can scale from one stream to 100? Either a hardware solution, or a solution using multiple PC's with some kind of encoding hardware? Broadcast quality SD and HD? What is the optimum format to output to the Wowza for rebroadcast via HTTP Live Streaming?

Thanks! What are some common platforms for doing this - I assume there are some expensive broadcast hardware platforms, and probably some free software platforms and some midrange PCIe card (or whatever slot is in new pc's these days) based solutions. What would I look at if I'm aiming for broadcast quality, or near broadcast quality at a reasonable price?